Moss Pigments. 7. Preliminary Investigations of the Violet Pigments in Sphagnum nemoreum.

Abstract

Two violet pigments of oxonium type are isolated from Sphagnum nemoreum Scop. Acid hydrolysis of one pigment gives the other one and an unstable acid. IR and UV data are compared with those of flavylium compounds. Transformations of the non-esterified pigment at pH 0.5[long dash]6.0 are studied by UV spectroscopy and compared with those of luteolinidin. The pK-values for the equilibria "violet acid" -[long dash] "yellow base", and luteolinidin [image]2,3[image],4,4[image],6-pentahydrox-ychalcone, for the violet pigment and luteolinidin, respectively, are determined. Polarographic reduction occurs at the same potential as that of 2 flavylium compounds studied. Some elemental analyses and chromatographic data are given.